Learn Hardcore Norwegian: Barna hopper fra bryggen om sommeren, men om vinteren står de bare og ser på havet. - The children jump from the pier in summer, but in winter they just stand and look at the sea.

De barna would be those children / the children (in contrast to others) and would sound more specific or contrastive than needed here. The neutral, general the children is just barna.

What exactly does hopper fra bryggen mean, and why is the preposition fra used?

Hopper fra bryggen = jump off the pier/jetty.

hoppe fra [noe] is the normal way to say jump off / jump from something (a chair, a roof, a pier, etc.).
fra = from/off (starting point).
av is not used here; hoppe av is used for things like hoppe av bussen (jump off the bus), but with a pier you normally say fra.
på bryggen would just mean on the pier (location), not the direction of the jump.

So hopper fra bryggen describes moving away from the pier, usually into the water.

What is bryggen, and why does it end in -en?

The noun is en brygge (a pier/jetty/wharf).

Indefinite singular: en brygge = a pier
Definite singular: bryggen = the pier

The -en ending marks the definite form for masculine nouns in Bokmål. So fra bryggen literally means from the pier.

(You may also see brygga as a definite form in more informal or dialectal Bokmål, but bryggen is the standard masculine form.)

Why is it om sommeren instead of something like i sommer or på sommeren?

Om sommeren here means in (the) summer / during summer (in general) and suggests a repeated or typical situation.

Nuances:

om sommeren
– Habitual / general: in (the) summer as a recurring time.
– Like: Barna hopper fra bryggen om sommeren = The children (typically) jump off the pier in summer.
i sommer
– Refers to this summer (either the coming one or the one just past), a specific summer, not a general habit:
– Barna hoppet fra bryggen i sommer = The children jumped off the pier this summer.
på sommeren
– Can be heard, but om sommeren is more idiomatic for the general, habitual meaning. På sommeren may sound more dialectal or less standard in this use.

So om sommeren is chosen because the sentence talks about what usually happens every summer.

Why does the word order change to men om vinteren står de bare ... and not men om vinteren de står ...?

Norwegian main clauses follow the V2 rule (verb-second):

One element in first position (subject, adverbial, etc.)
The finite verb in second position
The subject (if it wasn’t in first position)
The rest of the sentence

In men om vinteren står de bare og ser på havet:

om vinteren – adverbial, in first position
står – finite verb, second position
de – subject, comes after the verb

✗ men om vinteren de står ... breaks the V2 rule and sounds wrong in a normal main clause.

So the correct order after a fronted time expression like om vinteren is [time] + [verb] + [subject]:
Om vinteren står de ...

Why does the sentence use both står and ser in står de bare og ser på havet? Could it just be de ser bare på havet?

Both versions are possible, but they say slightly different things.

står de bare og ser på havet
– Literally: they just stand and look at the sea
– står ... og ser combines a posture verb (stå = stand) with another verb linked by og.
– This construction emphasizes how they are doing the action: they are standing there, doing nothing else, just looking.
de ser bare på havet
– Literally: they just look at the sea
– Focuses more on the action of looking, less on their physical position.

The original står de bare og ser ... paints a more visual, static picture: they are just standing still, staring at the sea.

What does bare mean in står de bare og ser på havet, and why is it placed there?

In this sentence, bare means just / simply, not only in a restrictive sense about who is doing something.

står de bare og ser på havet ≈ they just stand there and look at the sea
– It suggests that this is all they do; they don’t jump, swim, etc.

Placement:

står de bare og ser ...: bare modifies the whole action sequence står ... og ser (they merely stand and look).
You might also hear de bare står og ser ...; the nuance is tiny here and both are natural. The chosen order fits the V2 structure after om vinteren.

If bare came before barna (e.g. Bare barna hopper ...), then it would mean only the children jump ..., restricting who does the action instead of describing how they do it.

Why is it ser på havet and not just ser havet?

Norwegian distinguishes between:

å se (no object or direct object) = to see (perceive visually)
å se på [noe] = to look at / watch (actively direct your gaze at something)

In this sentence:

ser på havet = look at the sea / gaze at the sea
– They are actively looking in the direction of the sea.

If you said ser havet, it would more likely mean see the sea in the sense that the sea is visible to them, not necessarily that they are standing there, staring at it. That’s a weaker match for the intended image, so se på is used.

What is havet, and why is it in the definite form?

The noun is et hav (a sea, an ocean).

Indefinite singular: et hav = a sea
Definite singular: havet = the sea

In this context havet refers to the sea/ocean near the pier, something both speaker and listener can identify from context.

Ser på havet therefore means look at the sea, not look at a sea. Using the definite fits because there is usually one obvious body of water by the pier they’re looking at.

A bare form like på hav is not normal modern Norwegian here; you would say på havet.

Why is the present tense (hopper, står, ser) used, even though this describes what happens in summer and winter in general?

Norwegian, like English, uses the simple present to describe:

Habitual actions (what regularly happens)
General truths

So:

Barna hopper fra bryggen om sommeren
= The children (habitually) jump off the pier in summer.
... men om vinteren står de bare og ser på havet.
= ... but in winter they (habitually) just stand and look at the sea.

You could add pleier å (pleier å hoppe / pleier å stå) to make the habitual nature even more explicit, but it’s not necessary. The plain present tense already implies this regular, seasonal pattern.